Role of Putrescine on Androgen-Elicited Positive Inotropism in the Left Atrium of Rats
| Autor: | María José García de Boto, Javier Bordallo, Agustín Hidalgo, Lorena Secades, Lucía Velasco, Carmen Bordallo, Begoña Cantabrana, José M. Rubín, Manuel Sánchez |
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| Rok vydání: | 2008 |
| Předmět: |
Male
Agonist medicine.medical_specialty Cardiotonic Agents Eflornithine Spermidine medicine.drug_class Spermine In Vitro Techniques Biology Ornithine decarboxylase chemistry.chemical_compound Internal medicine Cyclic AMP Putrescine medicine Animals Heart Atria Rats Wistar Chromatography High Pressure Liquid Pharmacology Forskolin Colforsin Isoproterenol Dihydrotestosterone Adrenergic beta-Agonists Ornithine Decarboxylase Inhibitors Atrial Function Myocardial Contraction Rats Endocrinology chemistry Inotropism Androgens Cardiology and Cardiovascular Medicine Intracellular |
| Zdroj: | Journal of Cardiovascular Pharmacology. 52:161-166 |
| ISSN: | 0160-2446 |
| Popis: | Functional and biochemical studies were performed in isolated left atria of male Wistar rats to study whether endogenous polyamines may mediate androgen-elicited positive inotropism and their relationship with a rise in cAMP during the cardiotonic effect. 5 alpha-Dihydrotestosterone (100 microM) exposure increased intracellular putrescine as determined by HPLC, but it did not increase spermidine and spermine. This effect was antagonized by an inhibitor of ornithine decarboxylase, alpha-difluoromethylornithine (10 mM), suggesting enzyme activation. alpha-Difluoromethylornithine also antagonized androgens-elicited inotropism and the increase in intracellular cAMP. Putrescine (1 to 10 mM) elicited a concentration-dependent positive inotropism associated with the cAMP increase. The prior incubation with putrescine antagonized 5 alpha-dihydrotestosterone-elicited inotropism and did not produce sinergism on intracellular cAMP. Short-term incubation with 5 alpha-dihydrotestosterone or forskolin shifted to the left the cardiotonic effect of isoproterenol, an agonist of beta-adrenoceptors, without any increase in Emax, suggesting that a common mechanism was involved. Therefore, polyamines might modulate the cAMP production associated with the cardiotonic effect of androgens. |
| Databáze: | OpenAIRE |
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